EUGENE — After finishing a combined 11-14 the past two seasons, a culture change was needed in the Oregon football program.

As he enters his first season as head coach, Mario Cristobal says he has already seen the culture shift.

“Leaders are leading, and our culture is getting stronger, and we’re accomplishing what we need to do in an efficient manner,” Cristobal said Sunday during the Ducks’ media day at Autzen Stadium.

Cristobal is Oregon’s third head coach in three seasons, and he brings national championship experience to the position — he won two national titles as a player at Miami (1989 and 1991), and he won a national title as an assistant coach at Alabama (2015).

Cristobal is trying to bring the Ducks back to the level of success they enjoyed between 2009 and 2014, when they won four Pac-12 championships, won two Rose Bowls, competed in two national championship games and had a Heisman Trophy winner in Marcus Mariota.

The Ducks open the season at 5 p.m. Sept. 1 at home against Bowling Green. Here are three reasons for Oregon fans to be optimistic about this season, as well as three reasons for concern:

1. Experienced quarterback in Justin Herbert: As a junior, Herbert has a ton of hype surrounding him, including some Heisman talk, as well as talk of him possibly leaving Oregon after this season to enter the NFL Draft.

It can be difficult to avoid getting caught up in that noise, but Herbert is finding a way.

“It’s been a huge honor, for sure, but it hasn’t been as hard as people might think it would be,” he said. “I’ve got great guys around me, good friends who keep me down to earth. They need my best, just like I need it from them. I’m completely focused on this team.”

Herbert is bigger, stronger and more vocal than he was even last season, let alone his freshman year.

Cristobal said that in the year-plus he’s been in the program, he’s seen Herbert mature dramatically.

“He has more confidence about everything he does,” Cristobal said. “He’s obviously a tremendous student, well-liked by everyone in the building, the community, the state. He’s such a driven individual. He’s driven to get better, he’s never satisfied.”

2. Second season with defensive coordinator Jim Leavitt: When Leavitt joined the Ducks last season, he inherited a defense that ranked among the worst in the nation in 2016.

Under Leavitt, Oregon ranked 46th last season in total defense, allowing 369.2 total yards per game.

Now in their second season under Leavitt, the Ducks’ defense could jump into the top-25 and be one of the team’s biggest strengths.

“Instead of us all learning something new, like last year, everybody knows the base play-calls,” sophomore defensive tackle Jordon Scott said. “Now we’re working on bigger problems. The more we know, the more (Leavitt) can open up his toolbox.”

3. Depth and experience on the offensive line: Despite having no seniors among the group, Oregon’s offensive line enters the season with a wealth of experience.

Three offensive linemen — juniors Jake Hanson (center), Shane Lemieux (left guard) and Calvin Throckmorton (right tackle and right guard) — have started every game the past two seasons, a continuity that the Ducks’ offense will count on this season.

“There’s just that mesh that we have, having played 25 straight games together,” Throckmorton said. “That experience together is really important because it helps with communication pre-snap and understanding our responsibilities on each play and being able to play really fast.”

1. Depth at quarterback: The Ducks’ season derailed last year when Herbert went down with a fractured collarbone, and they had to use true freshman quarterback Braxton Burmeister as their starter in five games.

Oregon went 1-4 in those games, and the offense was one-dimensional with Burmeister, as he could not deliver the ball downfield.

Herbert, however, said that Burmeister dealt with a tough situation that would have been difficult on any young quarterback.

“Braxton’s done an incredible job. He’s one of the guys who’s always there working hard. He’s a great guy off the field as well,” Herbert said. “The situation he was thrown into last year was really tough, and for anyone to be thrown into that situation, that’s about as good as anyone could have done.”

This season, in addition to Burmeister, the Ducks also have true freshman Tyler Shough as a reserve behind Herbert.

Developing both Burmeister and Shough into viable backup options will be key during the next few weeks before the start of the season.

“They both have been impressive,” Cristobal said. “They both run the offense extremely well. They’ve been really efficient with the ball.”

2. Lack of proven playmakers: With the loss of players like running back Royce Freeman and wide receiver Charles Nelson, the Ducks enter this season with unproven talent at the skill positions.

Senior running back Tony Brooks-James and junior wide receiver Dillon Mitchell are the top returners at their respective positions, but Oregon will need other guys to step up and make plays if the Ducks are going to be successful this season.

One name that keeps coming up is redshirt freshman running back CJ Verdell, who had a game-high 44 rushing yards and two touchdowns in the spring game.

“We got a glimpse of him in the springtime, of what his body has become,” Cristobal said, while emphasizing the importance of a redshirt season for many players. “He’s more explosive. He runs his feet through contact now. When he got here as a freshman, you could trip-tackle him, kind of knock him over. And now, you better put your hat on him, you better wrap him up pretty good and rally to the football because he’s going to be a tough guy to bring down.”

3. Lack of coaching stability: During the recent coaching change, the Ducks were able to keep much of the brain trust from last year’s staff — Mario Cristobal (co-offensive coordinator last year), offensive coordinator Marcus Arroyo, co-defensive coordinator Leavitt and co-defensive coordinator Joe Salave’a.

That almost never happens, and it was a good sign for Oregon.

However, the Ducks have had three head coaches in three years, and they lost nearly half their staff from last year when Willie Taggart bolted to Florida State. And that came after Oregon lost its entire staff when Mark Helfrich was fired following the 2016 season.

The instability has taken a toll.

“Playing for three different head coaches has definitely been a challenge,” junior linebacker Troy Dye said. “Three different philosophies, three different ways practices are run, three different mentalities. Guys have faced a lot of adversity.”